This invention relates to a sigmoidoscope for use in examination of the bowel or other body cavity and to sigmoidoscopy.
It is frequently necessary for a medical practitioner to inspect the colon or rectum of a patient. This procedure is commonly conducted with a sigmoidoscope which in the past consisted of a metal tube or speculum adapted at one end for insertion into the rectum of a patient and adapted at the other end for connection with a manifold. The manifold was provided with an observation window, a rubber bulb insufflator connectable via a spigot to the manifold and communicating with the interior of the speculum whereby the bowel may be pressurised, and an illuminator with which at least a portion of the bowel interior may be illuminated during examination. In the past, after use and before reuse on a subsequent patient, the metal tube was sterilised. Subsequently there were developed sigmoidoscopes in which parts coming in contact with the patient were designed to be thrown away after use to save the time and expense of cleaning and sterilising.
Presently used sigmoidoscopes employ a disposable speculum in the form of a hollow, light transmissive, plastic tube. The disposable speculum is purchased in a clean or sterile condition sealed in a bag together with a disposable obturator adapted for use with the speculum. In use the disposable speculum is coupled to a non-disposable fibre optic head which has a hinged window through which an obturator or biopsy instrument may be inserted and removed coaxially through the interior of the speculum.
A light source is operatively coupled with the speculum via the fibre optic head so as to illuminate a circumferential end edge of the speculum via fibre optics whereby light from the illumination means may be directed through the wall of the speculum into the anal canal, bowel, or other body cavity under examination. The fibre optic head is also provided with a spigot for connection, for example via a flexible communicating tube, to an insufflation bulb with which the bowel may be insufflated with air. After use the obturator is discarded.
Upon conclusion of an examination the inexpensive plastic disposable speculum is also disconnected from the fibre optic head and disposed of The fibre optic head together with the hinged window mounted thereto and, fibre optic illumination means costs in excess of $750 and are retained for use with another speculum. The insufflation bulb may be disconnected between uses but commonly remains connected to the fibre optic head.
Although the invention will be herein described with reference to sigmoidoscopy, it will be understood that the invention is equally applicable to other forms of endoscopy which involve inflation of an internal cavity to be examined and is not limited to instruments for use in bowel examination.
The present inventor has discovered a previously unrecognised potential for cross-infection from sigmoidoscopy.
It is an object of the present invention to provide an improved sigmoidoscope and an improved method for conducting sigmoidoscopy which avoids or ameliorates a disadvantage of the prior art.
According to one aspect the invention consists of a sigmoidoscope comprising at least one disposable part, in combination with means for insufflation of a body cavity with a medium via the sigmoidoscope; said medium being susceptible to contamination by a contaminant (as herein defined) during use of the sigmoidoscope; said insufflation means and said sigmoidoscope being connected, or adapted for connection, one to the other; the sigmoidoscope and/or the insufflation means being provided with disposable contamination prevention means or being so formed and arranged that no non-disposable part of the sigmoidoscope and no non-disposable part of the insufflation means is exposed to any contaminated medium during use of the sigmoidoscope.
Unless the context clearly requires otherwise, throughout the description and the claims, the words xe2x80x98comprisexe2x80x99, xe2x80x98comprisingxe2x80x99, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of xe2x80x9cincluding, but not limited toxe2x80x9d.
The sigmoidoscope may be an assembly including a plurality of disposable parts, for example a disposable speculum and a disposable eyepiece and may include one or more non-disposable components, for example an illuminator. The means for insufflation is commonly an inflation bulb together with a flexible hollow tube whereby the bulb communicates with the sigmoidoscope and in such case the insufflation medium is air.
A xe2x80x9ccontaminantxe2x80x9d as herein defined is any agent capable of infection and includes, without limitation, viruses, bacteria, fungii, protozoa, mycoplasma and organic or inorganic carriers of any of the above.
According to a second aspect the invention consists in a sigmoidoscope disposable part having means for connection to a reusable insufflation means and wherein the disposable part or the insufflation means includes disposable contamination prevention means for preventing contamination of the reusable insufflation means during sigmoidoscopy.
The disposable part may for example be a disposable speculum. Contamination prevention means may, for example, be a non-return valve, a filter such as a nanopore filter, an electrostatic precipitator or other means which prevent internal surfaces of the reusable insufflation means from becoming contaminated by, for example, contaminants which become airborne during a sigmoidoscopy procedure and transferred from the patient to the sigmoidoscope interior, or are transferred for example by wall contact of an instrument. It will be understood that the term xe2x80x9cinsufflation meansxe2x80x9d includes any tubing communicating between an insufflation bulb or other source of insufflation medium and the sigmoidoscope.
According to a third aspect the invention consists in a sigmoidoscope disposable part having insufflation means permanently connected therewith for disposal with the disposable part. Preferably the disposable part is a speculum.
According to a fourth aspect the invention consists in a method for preventing cross-contamination from a first patient to a second patient during sigmoidoscopy said method comprising the steps of
(1) Examining a body cavity of the first patient by means of a sigmoidoscope used in combination with insufflation means for introducing an insufflation medium to the body cavity, and
(2) Prior to examining the second patient, disposing of all parts of the sigmoidoscope and of the insufflation means which have been exposed to contaminants in the insufflation medium.
Other aspects of the invention relate to a disposable obturator.
It has hitherto been assumed that disposal of the speculum and obturator after each use suffices to avoid cross-contamination. The possibility of cross-contamination via the insufflation medium and internal surfaces of the non-disposable insufflation bulb has not previously been considered. In addition, with many current sigmoidoscope designs, there is communication between portions of the internal surface of the fibre optic bead or of the observation window and surrounding eyepiece which are exposed to the insufflation medium. The present inventor considered that there may be a potential for microorganisms to be passed from one patient to another and carried out tests as hereinafter described to examine the possibility of bacteria contaminating the inside surface of an insufflation bulb and connecting tubing and/or non-disposable fibre optic light head and thereby the potential for cross-contamination. The results have surprisingly revealed that there is a potential for cross-contamination during sigmoidoscopy. The present invention provides a modified apparatus and method whereby this previously unsuspected potential for cross-contamination can be avoided.